Puncturing devices are used, for example, by diabetics who need to check their blood sugar level several times daily. Puncturing devices are usually used with disposable puncturing elements that are designed for single use. Puncturing elements of this type can be inserted into the puncturing device like a cartridge.
A persistent goal in the development of puncturing devices has been to generate puncture wounds with as little pain as possible and from which sufficient quantities of bodily fluid can be obtained. The depth of penetration is relevant to both the pain sensation and sampling size obtained. In general, the pain sensation and the quantity of bodily fluid obtained from the puncturing wound increase as the puncturing depth increases. Puncturing devices are therefore required to make the puncturing depth as small as possible to reduce the pain sensation, but also to make the puncture deep enough to produce a quantity of bodily fluid sufficient for measuring.
In order to reduce the risk of an unsuccessful puncture, puncturing devices having a pressure sensor are known, for example, in U.S. Pat. No. 5,879,311, in which a puncturing motion is initiated automatically as soon as a press-on part receives pressure in excess of a minimum pressure. A puncturing device having a built-in pressure sensor is also described in Publication No. EP 1 360 933. However, in this puncturing device, a puncture is not initiated automatically once a minimum pressure is reached, but rather the pressure exerted on a press-on part is displayed as falling within one of three general pressure ranges, viz., low, normal, and high. The puncturing motion is initiated by pressing a button on the device housing.